Windows
Compatible applications
Quick Facts
Basic information about this file format
Extension
.FIT
File Type
Flexible and Interoperable Data Transfer
Category
Data
Best first step
Use compatible software
Quick Summary
A practical overview of the .fit file format
The FIT (Flexible and Interoperable Data Transfer) file format is a compact, binary file format designed specifically for the storage and sharing of data generated by sports, fitness, and health devices. Developed by ANT+ (a subsidiary of Garmin), it is the primary format used by Garmin wearables,…
File extension
.FIT
File type
Flexible and Interoperable Data Transfer
Category
Data
Recommended action
Open with a trusted compatible app
How to open a .fit file
Start with a trusted app that supports this format
- Check the file extension carefully and confirm that the file name really ends with .fit.
- Use software that supports this file type. If one app does not work, try another compatible program for the same platform.
- Update the application if the file was created by a newer version of the software.
- Scan files from unknown sources before opening them, especially documents, archives, scripts, installers, and executable files.
What is a .fit file?
File extension details and usage information
The FIT (Flexible and Interoperable Data Transfer) file format is a compact, binary file format designed specifically for the storage and sharing of data generated by sports, fitness, and health devices. Developed by ANT+ (a subsidiary of Garmin), it is the primary format used by Garmin wearables, bike computers, and other fitness sensors to record activities in real-time. Unlike text-based formats like GPX or TCX, FIT files are highly optimized for small file sizes and low memory usage, making them ideal for devices with limited storage and processing power. A FIT file consists of a series of data messages that can store a wide variety of information, including GPS coordinates, heart rate, cadence, power output, temperature, and lap splits. Because it is a binary format, it requires specific software or SDKs to decode, but its efficiency has made it the industry standard for professional athletes and fitness enthusiasts. The format is also extensible, allowing manufacturers to add custom data fields without breaking compatibility with existing software. Most major fitness platforms, such as Strava, TrainingPeaks, and Zwift, natively support FIT files for activity analysis and performance tracking.
Software Compatibility
Programs that may open or work with .fit files
macOS
Compatible applications
Linux
Compatible applications
Mobile
Mobile applications
Can .fit files be converted?
Options for saving or exporting this file to another format
In many cases, a .fit file can be converted by opening it in compatible software and using an option such as Save As, Export, or Convert. The available output formats depend on the file type and the application used.
- Use the original software that created the file when possible.
- Check whether the application supports exporting to common formats.
- Be careful with online converters when working with private, business, or sensitive files.
- If conversion fails, the file may be corrupted, incomplete, encrypted, or not actually a .fit file.
Why can't I open a .fit file?
Common reasons this file type may not open correctly
Wrong software
The file may require a specific program that supports the .fit format.
Incorrect extension
The file extension may have been renamed manually, even though the actual file format is different.
Corrupted file
The file may be incomplete, damaged during download, or transferred incorrectly.
Outdated app
Your software may need to be updated before it can open newer versions of this file format.
Frequently Asked Questions
Common questions about .fit files
To open a .fit file, use software that supports this file format.
- Garmin BaseCamp
- GoldenCheetah
- GPSBabel
- Garmin Training Center
- LoadMyTracks
Open the file in compatible software and look for options such as Save As, Export, or Convert. If no export option is available, the file may require a specialized converter or the original application that created it.
- Verify that the file extension is correct.
- Install or update compatible software.
- Try another application that supports this format.
- Check whether the file is corrupted, incomplete, or encrypted.
A file extension alone does not guarantee whether a file is safe or unsafe. Only open files from trusted sources, scan unknown files before opening them, and be especially careful with executable, script, archive, and document files.
File safety tips
Use caution with unknown files
Only open files from trusted sources. Before opening a .fit file, scan it with antivirus software, verify that the file extension is expected, and avoid running unknown executable, installer, macro-enabled document, or script files.